Topic: Volvo C303 Portal Axles?

[Jeffy]

I'm seeing more and more of these axles being used and I'm really interested in them.  (I know 6699 had them.)  I've been reading that you can get the axles for around $4000/pair.  That's for the 4x4 version with the 5.99:1 gears.  I'm not sure if the 6x6 7:1 are available, although, they would be a bit too low for something that needs to drive on the highways.

Strength wise, I'm hearing that they are between a Dana 44 and a Dana 60.  The spiders are the weak points since they are the same size as the D30.  Actually, I heard they can be replaced with a D30 Lunchbox locker.  I'm wondering if the carrier is the same or not.  Can you replace the carrier with a complete D30 Detroit or ARB?  Or would it be better to stick with the air lockers it comes with?

The other issue is the passenger side drop on the front axle.  From what I've read from 6699's account and a really vague one in CRAWL Magazine, you can pull the third-member, portals and flip the housing without any modifications.  The only other problem is the vacuum diaphragm that needs to be relocated.  Now does the original hole need to be filled in and a new one drilled or is there some sort of bracket that needs to be reattached?  Some Detailed close up picts would be nice if anyone has any.

Now with the mounting, I'm hearing that the axles will give me about 5" lift on stock springs (SUA).  I think the width is spot on with the correct wheels and stock flares which looks great.  I'm wondering if the spring perches are correct on the c303 or do they need to be moved.  If they need to be moved how do you move them?  They aren't like tube spring perches.  Again, anyone have pictures?  Bigger the better.

[dunklervogel]

Here is a guy putting a pair under his landcruiser.. comes with pics

http://www.pirate4x4.com/forum/showthread.php?t=398873

[Jeffy]

Here is a guy putting a pair under his landcruiser.. comes with pics

http://www.pirate4x4.com/forum/showthread.php?t=398873

Seen it.  Actually, he's also been featured in the newest issue of CRAWL Magazine.  It's not as useful a build since he's running coils and has a passenger side drop.

[6099]

I'm seeing more and more of these axles being used and I'm really interested in them.  (I know 6699 had them.)  I've been reading that you can get the axles for around $4000/pair.  That's for the 4x4 version with the 5.99:1 gears.  I'm not sure if the 6x6 7:1 are available, although, they would be a bit too low for something that needs to drive on the highways.

Strength wise, I'm hearing that they are between a Dana 44 and a Dana 60.  The spiders are the weak points since they are the same size as the D30.  Actually, I heard they can be replaced with a D30 Lunchbox locker.  I'm wondering if the carrier is the same or not.  Can you replace the carrier with a complete D30 Detroit or ARB?  Or would it be better to stick with the air lockers it comes with?

The other issue is the passenger side drop on the front axle.  From what I've read from 6699's account and a really vague one in CRAWL Magazine, you can pull the third-member, portals and flip the housing without any modifications.  The only other problem is the vacuum diaphragm that needs to be relocated.  Now does the original hole need to be filled in and a new one drilled or is there some sort of bracket that needs to be reattached?  Some Detailed close up picts would be nice if anyone has any.

Now with the mounting, I'm hearing that the axles will give me about 5" lift on stock springs (SUA).  I think the width is spot on with the correct wheels and stock flares which looks great.  I'm wondering if the spring perches are correct on the c303 or do they need to be moved.  If they need to be moved how do you move them?  They aren't like tube spring perches.  Again, anyone have pictures?  Bigger the better.

Hi Jeff.

If you can find one, seriously recommend them they are a blast. Been having too much fun.

Yes, the volvo 3rd member is very similar to Dana 30, even the volvo's shafts are same 27 spline with identical diametre to the 30s.

I would just leave the volvo 3rd member alone as it has an integral dog gear that you will need to run the factory vacuum locker. And the other reason why you can't use regular differentials is because the volvo crown gear NEEDS to spins backwards because the portal box does not have 3 gears like the Hummer ones. The Volvos achieve this 'backward spin' by putting the crown gear on the other side of the pinion.

and yeah, being vacuum operated, you just need to tap into the engine manifold. I have a small vacuum tank under the hood that feeds both the brakes and lockers. I use fuel line and no those fragile plastic lines to hook up the system. Some guys here toss the vacuum and repace it with a compressed air ram. This gives instant actuation of the locker. The vacuum system takes about half a feet of forward or backward motion before they engage or disengage.

Flipping the front axle is no problem. Remove th drop boxes with the axle shafts. Remove the third member (and relocate the locker dog gears to the opposite end.) Flip your tube around and relocate  vacuum diagphragm housing from botom to top. It is a matter of unscrewing it from the bottom and putting on a new nut on the top. Of course weld up the hole underneath. Also you will need to relocate the dog gear pivot from the bottom to the top.

The only problem you will encounter is that the front prop shaft now rides reallt close to the bellhousing. I use a 1" motor mount lift for  some clearance. But the shaft still makes contact. I suspect, this is due to the fac that  I don't have a trackbar in the front :P (love the flex!)

I have since converted to disc brakes which also gives me a 6x5.5 bolt pattern. This puts the wheels at least 2 inches out each side and makes the track similar to full width axles.

For the jeep, recommend you get the centred rear diff out of the 6x6. the 4x4s have offset rear diffs

currently I run the stock springs with add a leafs and 3 inch of body lift. If I have to do it again, I would have kept my old man emu, gotten rid of the body lift.

Pics!



FULL FLEX. Diff clears the fan and shroud. Not sure if it will clear a 4litre six oil pan. Vacuum housing and locker pivot has been moved to the top.



pitman arm/tierod end clears with some tweakign

the dog gear which you will have to relocate to the other side of the diff




The other half of the dog gears



crown gear sits on other side vs conventional diff

[6099]

strength-wise, even though they run the same size components as a dana 30 they are twice as strong since max torque is achieved only at the portal boxes.

[Jeffy]

Thanks for replying.  Now when you move the vacuum actuator, swing arms and dog gear, how do you remount it on the other side?  How much fabrication is required?  Cutting and welding?  I think I can see where the shaft was on that reinforced area in this pict.  I take it a new hole was drilled on the opposite side.  What hold the pin in place?

http://i23.photobucket.com/albums/b387/jmzyap/P8280132.jpg

Also how difficult is it to move the dog gear to the other side?  I take it the carrier has to come out.  Then are you just swapping the side gears from one side to the other?  Looks like to take it apart, it will require resetting the carrier.  From the looks of it the carrier requires spanners and not shims to set the carrier/ring gear.  How difficult is that?  I'm used to standard diffs.  I've heard of a guy out here that used a Lockright in place of the vacuum setup.  I'm kinda wondering if the carriers are the same.  Or close enough to use.

I think having the rear offset isn't going to be a big deal.  I'm not sure if the importers out here are willing mix and match parts from the 4x4 and 6x6.  I'll have to email them and see what they say.

Also, is the leaf spring distance the same as with the YJ?  It doesn't look like you had to move anything there.

From what I can see the D30 size axle shafts shouldn't be a problem since they are not load bearing.  In essence it's like having a Full-Floater axle.

To run the vacuum actuators shouldn't be a problem.  I have onboard air so I could regulate the pressure down and use that instead of having to tap into the engine vacuum.

Another thing I noticed is that you're Jeep is RHD so the steering will have to be flipped over.

Have any more pictures?  Disassembly of the third-member?  More of the actuator pivot arm and fork?

[6099]

Thanks for replying.  Now when you move the vacuum actuator, swing arms and dog gear, how do you remount it on the other side?  How much fabrication is required?  Cutting and welding?  I think I can see where the shaft was on that reinforced area in this pict.  I take it a new hole was drilled on the opposite side.  What hold the pin in place?

Yes, the reinforced are was where the original difflock arm pivot waswas. Great thing aboutthe pivots is that it's actually a bolt. So it was a matter of drilling new holes above and reattaching the bolt.

Also how difficult is it to move the dog gear to the other side?  I take it the carrier has to come out.  Then are you just swapping the side gears from one side to the other?  Looks like to take it apart, it will require resetting the carrier.  From the looks of it the carrier requires spanners and not shims to set the carrier/ring gear.  How difficult is that?  I'm used to standard diffs.  I've heard of a guy out here that used a Lockright in place of the vacuum setup.  I'm kinda wondering if the carriers are the same.  Or close enough to use.

Dog gear is held in place by a C-clip. Undo that and just reassemble to the other side gear. No need to disassemble carrier. 2 minute job. Sorry, don't know much else about the carrier.

I think having the rear offset isn't going to be a big deal.  I'm not sure if the importers out here are willing mix and match parts from the 4x4 and 6x6.  I'll have to email them and see what they say.

Only the rear most axle off a 6x6 has a centered diff.  So if someone buys the front and the middle, you may be in luck. 

Also, is the leaf spring distance the same as with the YJ?  It doesn't look like you had to move anything there.

The original config of the front axles were spring over. Flipping around, they became spring under. But the centre pin hole was off by half an inch, this answers your question. I opted to cut mine and rebuild new perches. Should have just re-drilled the original perches.

From what I can see the D30 size axle shafts shouldn't be a problem since they are not load bearing.  In essence it's like having a Full-Floater axle.

Yep, they're literally twice as strong on account of the 2.06 reduction at the portal hubs, where max torque is reached.

To run the vacuum actuators shouldn't be a problem.  I have onboard air so I could regulate the pressure down and use that instead of having to tap into the engine vacuum.

Vacuum is negatie pressure, so not sure how you would rig it up with an OBA system

Another thing I noticed is that you're Jeep is RHD so the steering will have to be flipped over.

Not a problem for u, there are more left hand drive tierods than Right hand ones as the majority of the trucks were used in Europe

Have any more pictures?  Disassembly of the third-member?  More of the actuator pivot arm and fork?

[Jeffy]

From the looks of it, you take off that little clip which holds the collar that sets the carriers spacing.  When you swapped the dog gear was there any readjusting necessary to the carrier?

Overall, I'm getting the feeling they didn't do anything to fancy with the axle so they could repair it in the field easier.

I'm kinda partial to the stock wheels and with a better booster the drums should work OK too.  I don't like mud.    The drums look rather large.  Are shoes a conventional size that's available off another vehicle or are they specialized?

Ah, I forgot it's run off vacuum not pressure!  Maybe use a separate vacuum pump for the lockers.

There seem to be two companies that import them into the US.

http://www.volvoc303.com/body_index.html
http://www.real4x4.com/index.shtml

The first one seems like a larger outfit.  I'm sure if they're importing them, they're getting space parts for them as well.  I still haven't found time to call them.

How much do these axles run for down where you're at?  I'm sure with shipping cost, it can't be cheap to import them to the West Coast.

[Mozman68]

One other question...is that face blacked out because you work for the CIA and are involved in some sort of deep cover guerrilla warfare on behalf of the United States that reports to a top secret organization funded by but not known to our government??   

[Jeffy]

Maybe he works for the CIA?   

I've been doing some more research.

I found the English Manuals

http://www.petrisimolin.com/ThePalsta/topic.asp?whichpage=6&ARCHIVEVIEW=&TOPIC_ID=21108
http://www.offroadtarvike.fi/taustatieto.html
http://pirate4x4.com/forum/showthread.php?t=539666
http://pirate4x4.com/forum/showthread.php?t=398873

Here's some specs from the Volvo303 group.

C303/TGB11 = 2 axle, axle ratio 5.99:1 (11 tooth pinion x 32 tooth ring gear = 2.90909 (x 2.06 reduction = 5.992727)
C304/TGB13 = 3 axle, axle ratio 7.10:1 (9 tooth pinion x 31 tooth ring gear = 3.444444 (x 2.06 reduction = 7.095555)
C306/TGB20 = 3 axle troop carrier, axle ratio 7.55:1 (9 tooth pinion x 33 tooth ring gear = 3.666666 (x 2.06 reduction = 7.553333)

Volvo portal axles:

Trackwidth = 60.6"
330 lbs for a front axle
286 lbs for a rear axle
8 on 8.75" lug pattern
standard 4 bolt driveshaft flange (Rover size)
Birfield front axle joint (Rover size)
Portal box reduction = 2.06:1
Portal box gears are straight cut
Vertical distance from axle midline to hub midline = 5"
Vaccuum operated locker front/rear, easily converted to cable.
3" square tube stamped steel housing with removable 3rd member

Fronts are pass. drop, can be flipped to make d-side with few mods.
Rear 306 axle is centered, 303 axle is offset 2".

Ground clearance with standard tires(36")/rims(16") = Volvo C-series, 15.5"

factory ratios:

9x33 = 3.666666 (x 2.06 = 7.553333:1)
9x31 = 3.444444 (x 2.06 = 7.095555:1)
11x32 = 2.90909 (x 2.06 = 5.992727:1)

axle specs:

Pinion gear 11 teeth, ring gear 32 teeth.
Portal drive gear 16 teeth, driven gear 33 teeth.
Drive gear 1.5 wide, driven gear 1.4 wide.
Drive axle major diameter 1.16 miner 1.06
Driven axle major diameter 1.745 minor 1.555
27 spline inner axle shafts
26 degree turning angle

Brakes:

11" drum brakes (Rover 109 drum can be turned & drilled to fit: 576974)
Part number front shoes RTC3424 (full set for complete front axle)
Part number rear shoes STC2797 (full set for complete front axle)
Part number wheel cylinder rear right 243296
Part number wheel cylinder rear left 243297
Wilwood sells a disc brake conversion (but it's not cheap)

Portal box bearings:

Small Bearing = TIMKEN JLM104948
Small Race = TIMKEN - JLM104910
Large Bearing = NTN 4T-JLM508748
Large Race = NTN 4T-JLM508710
Inner Oil Seal = STEFA CB 60X85X8
Retaining Nut = V1523031 MUTTER AXEL C3 17B73 (Available at Altyco Parts)

Axle “cover” 1563012-2 (front axle CV boots) can be found at Volvo USA.


------------------------------------------------------------------------------
The model range is officially called the C - series and comes in a large number of military and commercial formats. All the military models are prefixed by TGB although the body ID plates still carry the C series coding.

The military models available are as follows

    TGB 11   - Command Cab 4x4
    TGB1111- Anti-Tank canvas top 4x4
    TGB 13   - Command Cab 6x6
    TGB1312 - radio box 6x6
    TGB1314 - Ambulance body 6x6
    TGB 20   - Troop Transport 6x6 (canvas top, cab and box)
     

    Also available in 6x6
    ambulance body (cab and box)
    Fitted For Radio (cab and box)
    Commercial (12V) Fire trucks in 4x4, 6x6 and LWB 6x6 (proverbial hen's teeth)
     

The Volvo C303 was built between 1974 - 1982. It came in different forms including a soft top and hard top 4x4, a 6x6 in various forms in military and civilian 4x4 version. The C303 has leaf springs with straight, portal axles, approx. 380mm of clearance at the lowest point. High and low range transfer case, a 6 cylinder Volvo B-30 engine and a 4 speed transmission (5 speed available in some later models). They come with fully selectable vacuum operated diff. lockers on the front and rear.

Top speed: 70mph (4x4) 60mph (6x6) 50mph (troop carrier 6x6)
Power: 125hp at 4200 RPM  - Civilian model only, military power unknown but thought to be ~110bhp
Torque: 165 Ft.lbs. at 2500 RPM
Dimensions: 4240mm, width: 1930mm, height: 2130mm
Turning radius: 5m
Weight: 2400kg (unladen); GVM 3450kg (4x4)  2800kg (6x6)
Engine: Volvo B30A, 2982cc, petrol, 6-cyls, Twin Stromberg carb fed, 2-valves/cyl, ohv. Bore: 88.9mm, stroke: 80mm, CR: 9.3:1 (civ)
Transmission: 4sp, part-time 4WD (6WD), 2-speed transfer case, portal axles with 2:1 hub reduction gears, front and rear diff locks


Suspension: Live-leaf/live-leaf
Brakes: Drum/drum (as from a Landrover 109 V8)
Tyres: 9x16"
Fuel tank: 85L

[dunklervogel]

Those are some pretty crazy gear ratios.  Wouldn't be bad if you wanted to run tires in the 38-40" range I suppose.

Overall though, it seems like if someone were to get ahold of these axles they'd make for a great swap.  Lockers, lowlowLOW gearing, and adds some extra lift too. 

Definately wouldn't want to run 31s though or its dumptruck shifting time!   Who needs a 4:1 xfer case 

[Jeffy]

Those are some pretty crazy gear ratios.  Wouldn't be bad if you wanted to run tires in the 38-40" range I suppose.

Overall though, it seems like if someone were to get ahold of these axles they'd make for a great swap.  Lockers, lowlowLOW gearing, and adds some extra lift too. 

Definately wouldn't want to run 31s though or its dumptruck shifting time!   Who needs a 4:1 xfer case 

Actually they aren't that low for a 4banger.  You can run the 5.99:1's fairly easily and still drive on highways.  The 7's are a bit low though for a daily driver.  Also, you can't run really large tires.  Like 6699 says, there are D30 size parts there.  The weak points are the spider gears since they're D30 size.  I think the limit is around 38".  Anything larger and you risk breaking parts.  I'd still consider running a 4:1 box of some sort though.  With a stock transfer cans and transmission the low is only 64:1.  With a 4:1 of some sort, it drops to 94:1 which is pretty good.  Still, for some trails out west 200:1 is a real sweet spot.

[6099]

From the looks of it, you take off that little clip which holds the collar that sets the carriers spacing.  When you swapped the dog gear was there any readjusting necessary to the carrier?

No readjusting the carrier, just undo C clip, bring it to the other side, reattach C-clip

Overall, I'm getting the feeling they didn't do anything to fancy with the axle so they could repair it in the field easier.

I'm kinda partial to the stock wheels and with a better booster the drums should work OK too.  I don't like mud.    The drums look rather large.  Are shoes a conventional size that's available off another vehicle or are they specialized?

The drums and cylinders are off a Series 3 Land Rover 109s. The front operates on 2 cylinders per wheel and are pretty strong. I could lock the front wheels on tarmac! Never could do that with tthe stock jeep disc brakes. The rear uses a conventional single cylinder.

Ah, I forgot it's run off vacuum not pressure!  Maybe use a separate vacuum pump for the lockers.

There seem to be two companies that import them into the US.

http://www.volvoc303.com/body_index.html
http://www.real4x4.com/index.shtml

The first one seems like a larger outfit.  I'm sure if they're importing them, they're getting space parts for them as well.  I still haven't found time to call them.

How much do these axles run for down where you're at?  I'm sure with shipping cost, it can't be cheap to import them to the West Coast.

[6099]

Those are some pretty crazy gear ratios.  Wouldn't be bad if you wanted to run tires in the 38-40" range I suppose.

Overall though, it seems like if someone were to get ahold of these axles they'd make for a great swap.  Lockers, lowlowLOW gearing, and adds some extra lift too. 

Definately wouldn't want to run 31s though or its dumptruck shifting time!   Who needs a 4:1 xfer case 

Actually they aren't that low for a 4banger.  You can run the 5.99:1's fairly easily and still drive on highways.  The 7's are a bit low though for a daily driver.  Also, you can't run really large tires.  Like 6699 says, there are D30 size parts there.  The weak points are the spider gears since they're D30 size.  I think the limit is around 38".  Anything larger and you risk breaking parts.  I'd still consider running a 4:1 box of some sort though.  With a stock transfer cans and transmission the low is only 64:1.  With a 4:1 of some sort, it drops to 94:1 which is pretty good.  Still, for some trails out west 200:1 is a real sweet spot.

The competition guys here run Toyota 2JZ engines (280hp stock) and 36" tires. And believe me, they don't go lightly on the gas. The volvos seem to survive. Most often, we see them break only when landing the front end with the engine on full throttle And that's always the birfield exploding.

With the 4banger, you're never going to break anything... : )

PS: the guy's just dog ugly, had to black out : )